The role of maternal diet including or excluding highly allergenic foods in the development of food allergy in the infants is still unclear. There are no randomized controlled trials assessing maternal food allergen consumption during pregnancy or lactation on development of allergy to foods, including milk, egg or peanut in their infants. Retrospective studies, which are subject to recall bias and reverse causality have reported conflicting findings; so have murine models. The significant limitation to all the studies assessing the impact of maternal ingestion of peanut during lactation on infant's risk of food allergy is that the presence and the amount of maternal dietary antigen transmitted to human milk was not assessed. Because published data has documented variable levels of food antigens in human milk, this seems an apparent variable to control for in future clinical trials that include or exclude food antigens in mother's diet to assess development of food allergy in infants. In addition, birth cohort studies that assess development of multiple food allergies would benefit from a method to allow detection of multiple common food antigens simultaneously from human milk samples. In addition, a clinical conundrum encountered in daily management of breastfed infants is whether a mother needs to avoid highly allergenic foods if her infant shows symptoms suggestive of food allergies. There is no commercially available, validated assay for detecting food antigens in human milk. The published data report large variation in peak concentration of peanut and results on kinetics are contradictory. Other common food allergens, such as cow's milk, hen's egg and wheat are not as well-studied. Therefore, we propose to develop the assay on a platform that easily allows multiplexing to assess a variety of allergens at once, thereby providing a broad picture of the nature and kinetics of food exposure through mother's milk, which could be utilized in future maternal dietary intervention and general cohort studies assessing development of food allergy in the infant. Furthermore, we propose to verify the biologic functioning of the detected antigen by current gold standard, basophil activation test (BAT) and to compare levels between mothers with healthy infants and those with infants with symptoms suggestive of food allergies. Subsequently, this assay could be expanded to other food antigens and used to characterize the circumstances in which mother's dietary antigens are transmitted in their milk and should be avoided for the benefit of the infant. This would provide personalized medicine therapies for breastfed infants suffering from food allergies with significant nutritional and quality of life impact. 1